Lots of good information on this site. I have been sweating all the details on attaching a deck ledger to a lower portion of the house when a light bulb came on. Don't connect it at all. Free standing makes a lot of sense, you don't compromise the house at all.
The deck is low enough (2-4' from deck surface to grade) where I can raise the 12" round footings right up to the beam (4x8). When placing the anchors in the concrete, it doesn't seem like you have a lot of wiggle room. A post you can cut to exact height and if the beam is slightly bowed a post can be adjusted laterally. However I thought there might be a problem with short posts splitting.
I would probably line up all the metal anchors along a taught line but the beam more than likely wouldn't drop in. I could connect the anchors to the beam first and set them in concrete in one finished assembly. That would require a lot of guys handling the concrete real fast.
How would you approach this? Deck dimensions are 8x16'
I've never tried it but if you place the beam in position with some temp braces before the pour you'ld have all the time you want for the pour. Put together a small plywood chute to help direct the crete into the smaller opening. Make sure you vibrate or rod around the metal anchor.